A1 Form Due To Double NI Contributions in UK and Abroad

Hello, I need an A1 Form to prove that I have paid National Insurance in the UK since 2018 (in fact I have been paying since 2007). I have been double-charged National Insurance in Greece although I work full-time in the UK and I am a full-time resident. I applied for an A1 form on 23 May and received a generic letter on 6 September (15 weeks later) saying that I am not entitled to a certificate because my posting is longer than 24 months. This sounds forward-looking. There is no posting. I would like a certificate confirming that I have been paying National Insurance for the last few years. I can't afford to wait another 15 weeks as the NI bills in Greece are piling up and they claim I already owe them €14k!... Can you please help? 

Hi Alexander Kyrtsis,
You will need please to call us and ask for someone to look at your application again, as it would appear that there has been a misunderstanding.
Without looking at your application we cannot determine how the misunderstanding occurred.
Alternatively you can apply again online using the CA8421 application, and we will take a further look at your application.
Thank you. 
 

Thank you for this. I spoke to the telephone service but they don't seem to be able to help in any way. The said they will try to get somebody to call me back but they didn't sounded too confident this will happen. I'll wait a few days...